Liquid supplying device and liquid supplying method

ABSTRACT

The present invention provides a liquid supplying device that can determine whether a CLC can be used appropriately. A liquid supplying device for supplying a liquid from a liquid source to a cleaning device is provided. The liquid supplying device includes a flow rate control device that measures a flow rate of a liquid from the liquid source and controls the flow rate based on the measured value, an IN-side pressure gauge provided between the liquid source and the flow rate control device and an OUT-side pressure gauge provided between the flow rate control device and the cleaning device.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. patent application No.15/942,743, filed on Apr. 2,2018, which is based upon and claims benefitof priority from Japanese Patent Application No. 2017-073791 filed onApr. 3, 2017, the entire contents of which are incorporated herein byreference.

TECHNICAL FIELD

The present invention relates to a liquid supplying device and a liquidsupplying method.

BACKGROUND ART

A CMP (chemical mechanical polishing) device includes a polishing devicefor polishing a surface of a semiconductor substrate on which asemiconductor chip is formed and a cleaning device for cleaning thesemiconductor substrate polished by the polishing device while supplyinga cleaning chemical. This cleaning device creates a cleaning chemical(diluted chemical) by a chemical with mixing dilution water such as DIW(De-Ionized Water) and cleans the semiconductor substrate by using thecleaning chemical (see, for example, Japanese Patent Laid-Open No.2009-54959).

Cleaning devices using a cleaning chemical conventionally use a CLC(closed loop controller) that measures a flow rate of a liquid andcontrols the flow rate based on the measured value. The CLC can controlflow rates of the chemical and DIW and supply the chemical which isdiluted at a predetermined ratio to the cleaning device.

As a flowmeter provided inside the CLC, a differential pressure typeflowmeter (orifice flowmeter) is generally used. With an orifice placedin a path through which a fluid passes, the differential pressure typeflowmeter measures a volume flow rate (flow speed) of the fluid based onthe differential pressure. A measurement range of the differentialpressure type flowmeter, that is, a flow rate range that can becontrolled by the CLC structurally falls within a range predeterminedaccording to a diameter of the orifice, for example, from 30 ml/min to300 ml/min. For example, in the case of the CLC provided with anultrasonic type flowmeter, its controllable flow rate range is definedto be a predetermined range.

In the conventional cleaning chemical supplying device, when a dilutionratio of the cleaning chemical is changed in association with a changein a process recipe or the like or when a flow rate of the cleaningchemical supplied is changed, the flow rates of the required chemicaland the DIW may deviate from the flow rate range that can be controlledby the currently selected CLC. In that case, the change in the processrecipe is handled by replacing the CLC by a CLC having a controllableflow rate range.

SUMMARY OF INVENTION Technical Problem

The flow rate range that can be controlled by the CLC becomes the rangedefined as described above. However, the flow rate that can be actuallysupplied by the CLC to the cleaning device varies depending on adifferential pressure between an IN-side pressure and an OUT-sidepressure of the CLC. That is, the above-described controllable flow raterange of the CLC is a maximum flow rate range when the differentialpressure is sufficiently large, and when the differential pressure isinsufficient, only a flow rate that is less than the maximum flow ratecan be supplied to the cleaning device.

When the CLC is changed in association with a change in the processrecipe or the like, the conventional cleaning chemical supplying deviceselects the CLC based on the controllable flow rate range. When thedifferential pressure between an IN-side pressure and an OUT-sidepressure of the CLC is sufficiently large, the selected CLC can supply acleaning chemical at a desired flow rate to the cleaning device.However, when the differential pressure is insufficient as describedabove, even when a CLC having an appropriate flow rate range isselected, a cleaning chemical at a desired flow rate cannot be suppliedto the cleaning device. One cause that the CLC cannot supply a desiredflow rate can be a malfunction of the CLC. For this reason, when adesired flow rate cannot be supplied, it is not possible to determinewhether the CLC malfunctions or the differential pressure isinsufficient.

The present invention has been implemented in view of theabove-described problems, and it is one of objects of the presentinvention to provide a liquid supplying device capable of determiningwhether the CLC can be appropriately used or not.

Solution to Problem

According to an aspect of the present invention, a liquid supplyingdevice for supplying a liquid from a liquid source to a cleaning deviceis provided. This liquid supplying device includes a flow rate controldevice that measures a flow rate of the liquid from the liquid sourceand controls the flow rate based on the measured value, an IN-sidepressure gauge provided between the liquid source and the flow ratecontrol device and an OUT-side pressure gauge provided between the flowrate control device and the cleaning device.

According to another aspect of the present invention, a liquid supplyingmethod is provided for a liquid supplying device provided with a flowrate control device that measures a flow rate from a liquid source andcontrols the flow rate based on the measured value, to supply a liquidfrom the liquid source to a cleaning device. The liquid supplying methodincludes a flow rate controlling step of measuring a flow rate from theliquid source and controlling the flow rate based on the measured value,a first measuring step of measuring a pressure of a liquid flowing intothe flow rate control device and a second measuring step of measuring apressure of a liquid flowing out from the flow rate control device.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic front view illustrating a chemical supplyingdevice according to a first embodiment;

FIG. 2 is a diagram illustrating a chemical supply flow of the chemicalsupplying device according to the first embodiment;

FIG. 3 is a schematic front view illustrating a chemical supplyingdevice according to a second embodiment; and

FIG. 4 is a diagram illustrating a chemical supply flow of the chemicalsupplying device according to the second embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present invention will be described withreference to the accompanying drawings. In the drawings describedhereinafter, identical or equivalent components are assigned identicalreference numerals and duplicate description is omitted. Although achemical cleaning device will be described hereinafter as an example ofa liquid supplying device, without being limited to this, the presentinvention includes any liquid supplying device that can supply a liquidto a cleaning device.

First Embodiment

FIG. 1 is a schematic front view illustrating a chemical supplyingdevice according to a first embodiment. The chemical supplying deviceaccording to the present embodiment is configured to be able to supplyan acid or alkaline first chemical to a cleaning device. As shown inFIG. 1, the chemical supplying device 100 includes a housing 101, aDIWCLC box 110 and a first chemical CLC box 120. The DIWCLC box 110controls a supply of DIW (corresponding to an example of dilutionwater). The first chemical CLC box 120 controls a supply of a firstchemical.

The chemical supplying device 100 is further provided with chemicalutility boxes 50 for introducing the first chemical from a firstchemical supply source 20 (see FIG. 2) to the chemical supplying device100. In the example shown in the drawing, the chemical supplying device100 is provided with six chemical utility boxes 50, but these are merelyexamples and the number of the chemical utility boxes 50 is changed asappropriate depending on a specification of the cleaning device.

The DIWCLC box 110, the first chemical CLC box 120 and the chemicalutility boxes 50 are housed in the housing 101. The DIWCLC box 110 isconfigured to supply DIW from a DIW supply source 10 which will bedescribed later to a first in-line mixer 72 which will be describedlater (see FIG. 2). Furthermore, the DIWCLC box 110 can control the flowrate of DIW to a flow rate set through feedback control.

The first chemical CLC box 120 is configured to supply the firstchemical from the first chemical supply source 20 to the first in-linemixer 72 which will be described later (see FIG. 2). Furthermore, thefirst chemical CLC box 120 can control a flow rate of the first chemicalto the flow rate set through feedback control. The chemical supplyingdevice 100 includes a pipe for transporting the DIW or the firstchemical, a valve and a pressure gauge or the like, which are not shown.Details thereof will be described in FIG. 2.

FIG. 2 is a diagram illustrating a chemical supply flow of the chemicalsupplying device 100 according to the first embodiment. As shown in FIG.2, the chemical supplying device 100 is configured to be in fluidcommunication with the DIW supply source 10 (corresponding to an exampleof the dilution water supply source) for supplying the DIW and the firstchemical supply source 20 for supplying the first chemical via theirrespective pipes. The chemical supplying device 100 is also configuredto be in fluid communication with a cleaning device 200. Morespecifically, the chemical supplying device 100 supplies DIW and thediluted first chemical (first cleaning chemical) to the cleaning device200.

The cleaning device 200 includes a DIW cleaning section 210 that cleansa cleaning target such as a semiconductor substrate polished by apolishing device using DIW and a chemical cleaning section 220 thatcleans a cleaning target such as a semiconductor substrate polished by apolishing device using a diluted first chemical (first cleaningchemical). The DIW cleaning section 210 is constructed of, for example,an ultrasonic water cleaning section or other DIW cleaning sections. Thechemical cleaning section 220 is constructed of, for example, a rolltype cleaning section. The DIW cleaning section 210 and the chemicalcleaning section 220 coexist in a same cleaning tank 230.

The chemical supplying device 100 is provided with the first in-linemixer 72, the first chemical CLC box 120 and the DIWCLC box 110. Thefirst in-line mixer 72 mixes the first chemical and the DIW to generatea first cleaning chemical. The first chemical CLC box 120 controls theflow rate of the first chemical supplied from the first chemical supplysource 20 to the first in-line mixer 72. The DIWCLC box 110 controls theflow rate of the DIW supplied from the DIW supply source 10 to the firstin-line mixer 72.

The DIWCLC box 110 includes a first DIW supply valve 112 and a CLC 111(corresponding to an example of the dilution water flow rate controldevice). The first DIW supply valve 112 switches ON/OFF of DIW supplyfrom the CLC 111 to the first in-line mixer 72. The CLC 111 measures aflow rate of DIW supplied to the first in-line mixer 72 and controls theflow rate based on the measured value. More specifically, the CLC 111adjusts (performs feedback control) opening of a control valve insidethe CLC 111 based on the measured flow rate of DIW so that the flow rateof DIW flowing into the CLC 111 becomes a desired flow rate. The DIWCLCbox 110 supplies the DIW to the first in-line mixer 72 by opening thefirst DIW supply valve 112.

The first chemical CLC box 120 includes a first chemical supply valve122 and a CLC 121 (corresponding to an example of the chemical flow ratecontrol device). The first chemical supply valve 122 switches ON/OFF offirst chemical supply from the CLC 121 to the first in-line mixer 72.The CLC 121 measures a flow rate of the first chemical supplied to thefirst in-line mixer 72 via the first chemical supply valve 122 andcontrols the flow rate based on the measured value. More specifically,the CLC 121 adjusts (performs feedback control) opening of the controlvalve inside the CLC 121 based on the measured flow rate of the firstchemical so that the flow rate of the first chemical flowing into theCLC 121 becomes a desired flow rate.

The chemical supplying device 100 is provided with the chemical utilityboxes 50. The chemical utility boxes 50 introduce the first chemicalfrom the first chemical supply source 20 to the CLC 121 of the firstchemical CLC box 120. The chemical utility boxes 50 are provided on apipe 91 connecting the first chemical supply source 20 and the CLC 121of the first chemical CLC box 120. Each chemical utility box 50 isprovided with a manual valve 53, a first chemical inlet valve 51 thatswitches ON/OFF of first chemical supply to the CLC 121 and a pressuregauge 52 (corresponding to an example of the chemical IN-side pressuregauge) that measures a fluid pressure in the pipe 91. Opening/closing ofthe first chemical inlet valve 51 is controlled by, for example, acontrol device (not shown). Since the pipe 91 is connected to the CLC121 of the first chemical CLC box 120, the pressure gauge 52 isconfigured to measure a pressure of the IN-side (primary side) of theCLC 121. In other words, the pressure gauge 52 measures a pressure ofthe first chemical flowing into the CLC 121.

The chemical supplying device 100 is provided with a DIW supply pipe 81,one end of which is connected to the DIW supply source 10 and the otherend of which is connected to the DIW cleaning section 210 of thecleaning device 200. The DIW supply pipe 81 is provided with a DIWsupply valve 86, a DIW pressure adjusting regulator 87 and a DIWpressure gauge 88. By being opened/closed, the DIW supply valve 86controls a supply of the DIW from the DIW supply source 10 to the DIWsupply pipe 81. The DIW pressure adjusting regulator 87 adjusts a supplypressure of the DIW from the DIW supply pipe 81 to the DIW cleaningsection 210. The DIW pressure gauge 88 measures the pressure of the DIWpassing through an interior of the DIW supply pipe 81.

One end of a DIW branch pipe 82 is connected between the DIW supplyvalve 86 and the DIW pressure adjusting regulator 87 on the DIW supplypipe 81. The other end of the DIW branch pipe 82 is connected to the CLC111 of the DIWCLC box 110. A DIW pressure adjusting regulator 77 and apressure gauge 76 are provided on the DIW branch pipe 82. One end of afirst DIW pipe 83 is connected to the CLC 111. The other end of thefirst DIW pipe 83 is connected to a first chemical pipe 93 which will bedescribed later at a confluence part 78 and is in fluid communicationwith the first in-line mixer 72. Note that as shown in FIG. 2, theconfluence part 78 is a point of confluence where the DIW from the CLC111 and the first chemical from the CLC 121 joint together. The firstDIW supply valve 112 is provided on the first DIW pipe 83 andopening/closing thereof is controlled when the DIW is supplied to thefirst in-line mixer 72.

In the chemical supplying device 100 according to the presentembodiment, a pressure gauge 76 (corresponding to an example of adilution water IN-side pressure gauge) is provided on the IN-side of theCLC 111. More specifically, the pressure gauge 76 is provided betweenthe DIW pressure adjusting regulator 77 and the CLC 111 in the examplein FIG. 2. This pressure gauge 76 measures a pressure of the DIW flowinginto the CLC 111.

A first chemical pipe 93 in fluid communication with the first in-linemixer 72 is connected to the CLC 121 of the first chemical CLC box 120.The first chemical supply valve 122 is provided on the first chemicalpipe 93 and opening/closing thereof is controlled when the firstchemical is supplied to the first in-line mixer 72. A first cleaningchemical pipe 96, one end of which is connected to the chemical cleaningsection 220 is connected to the first in-line mixer 72. A pressure gauge74 (corresponding to an example of the OUT-side pressure gauge) isprovided on the OUT-side (secondary side) of the first in-line mixer 72.Since the DIW from the CLC 111 of the DIWCLC box 110 and the firstchemical from the CLC 121 of the first chemical CLC box 120 jointogether at the confluence part 78, the pressure on the OUT-side(secondary side) of the CLC 111 is equal to the pressure on the OUT-sideof the CLC 121. Therefore, this pressure gauge 74 can measure pressureson the OUT-side of the CLC 111 and the CLC 121. In other words, thepressure gauge 74 measures pressures of liquids flowing out from the CLC111 and the CLC 121.

The CLC 111 of the DIWCLC box 110 and the CLC 121 of the first chemicalCLC box 120 are configured to be able to receive signals indicatingpredetermined flow rate values from a control device (not shown).Openings of inner control valves of the CLC 111 and the CLC 121 arecontrolled based on the flow rate values.

Next, a chemical supply process in which the chemical supplying device100 shown in FIG. 2 supplies the first cleaning chemical to the chemicalcleaning section 220 will be described. When the first cleaning chemicalis supplied to the chemical cleaning section 220, the first chemicalinlet valve 51 of the chemical utility box 50 is opened first and themanual valve 53 is then opened. The CLC 121 of the first chemical CLCbox 120 measures the flow rate of the first chemical and controls theflow rate based on the measured value. The first chemical at apredetermined flow rate is supplied to the first in-line mixer 72 fromthe first chemical supply source 20 via the CLC 121 and the confluencepart 78.

When the DIW supply valve 86 on the DIW supply pipe 81 is opened, theDIW is supplied from the DIW supply source 10 to the CLC 111 of theDIWCLC box 110. The CLC 111 measures the flow rate of the DIW andcontrols the flow rate based on this measured value. When the first DIWsupply valve 112 is opened, the DIW is supplied from the DIWCLC box 110to the first in-line mixer 72 via the confluence part 78. The firstchemical and the DIW are mixed at the first in-line mixer 72. The firstcleaning chemical generated in this way is supplied to the chemicalcleaning section 220 via the first cleaning chemical pipe 96.

When the first cleaning chemical is supplied to the chemical cleaningsection 220, the pressure gauge 76, the pressure gauge 52 and thepressure gauge 74 measure a pressure on the IN-side of the CLC 111, apressure on the IN-side of the CLC 121 and pressures on the OUT-side ofthe CLC 111 and the CLC 121 respectively. It is thereby possible toobtain a differential pressure between the IN-side pressure and theOUT-side pressure of the CLC 111 and a differential pressure between theIN-side pressure and the OUT-side pressure of the CLC 121.

As described above, flow rate ranges that can be controlled by the CLCs111 and 121 are determined based on the structure of the flowmeterprovided inside. However, the flow rate of the liquid that can beactually supplied to the cleaning device 200 from the CLC 111 or 121varies depending on a differential pressure between the IN-side pressureand the OUT-side pressure of the CLC 111 or 121. That is, the flow raterange that can be controlled by the CLC 111 or 121 is a maximum flowrate range when the differential pressure is sufficiently large, andwhen the differential pressure is insufficient, only a flow rate smallerthan the maximum flow rate can be supplied to the cleaning device 200.

When the CLC is changed in association with a change in the processrecipe, the conventional chemical supplying device selects a CLC basedon the controllable flow rate range. Therefore, when the differentialpressure between the IN-side pressure and the OUT-side pressure of theCLC is sufficiently large, the selected CLC can supply a cleaningchemical at a desired flow rate to the cleaning device. However, asdescribed above, when the differential pressure is insufficient, evenwhen a CLC having an appropriate flow rate range is selected, it is notpossible to supply the cleaning chemical at the desired flow rate to thecleaning device. One cause that the CLC cannot supply a desired flowrate may be attributable to a malfunction of the CLC. For this reason,when the desired flow rate cannot be supplied, it is not possible todetermine whether the CLC is malfunctioning or the differential pressureis insufficient.

In contrast, in the present embodiment, it is possible to obtain adifferential pressure between the IN-side pressure and the OUT-sidepressure of the CLC 111 and a differential pressure between the IN-sidepressure and the OUT-side pressure of the CLC 121 as shown in FIG. 2. Inthis way, even if the CLC 111 or the CLC 121 cannot supply a desiredflow rate, the operator can grasp whether the CLC 111 or the CLC 121 ismalfunctioning or the differential pressure is insufficient bymonitoring the differential pressure.

By acquiring the differential pressure between the IN-side pressure andthe OUT-side pressure of the CLC 111 and the differential pressurebetween the IN-side pressure and the OUT-side pressure of the CLC 121,it is possible to easily select an appropriate CLC when changing the CLC111 or the CLC 121 in association with a change in the process recipe.More specifically, a CLC may be selected which can supply a desired flowwith a differential pressure achieved at the present time among variousCLCs having different controllable flow rate ranges. Note that the CLChas a relationship between a differential pressure and a controllableflow rate range as a feature thereof and the relationship is acquired inadvance.

The pressure gauge 74 in the present embodiment is provided on thesecondary side of the first in-line mixer 72, but without being limitedto this, the pressure gauge 74 may be provided at any place if it ispossible to measure a pressure on the OUT-side of the CLC 111 or the CLC121. For example, the pressure gauge 74 can be provided on the OUT-sideof the DIWCLC box 110 or on the OUT-side of the first chemical CLC box120 or the like.

Second Embodiment

FIG. 3 is a schematic front view illustrating a chemical supplyingdevice according to a second embodiment. The chemical supplying deviceaccording to the present embodiment is different from the chemicalsupplying device shown in the first embodiment in that it uses two kindsof chemicals. That is, the chemical supplying device is configured to beable to supply a first chemical which is, for example, an alkalinechemical and a second chemical which is, for example, an acid chemicalto a cleaning device. Therefore, the chemical supplying device 100according to the second embodiment includes a second chemical CLC box130 in addition to the configuration of the chemical supplying device100 shown in FIG. 1. The second chemical CLC box 130 controls a supplyof the second chemical. The chemical supplying device 100 is alsoprovided with chemical utility boxes 60 for introducing the secondchemical from a second chemical supply source 30 (see FIG. 4) to thechemical supplying device 100.

FIG. 4 is a diagram illustrating a chemical supply flow of the chemicalsupplying device 100 according to the second embodiment. As shown inFIG. 4, the chemical supplying device 100 according to the secondembodiment is provided with a mechanism for supplying a second chemicalin addition to the configuration of the chemical supplying device 100according to the first embodiment. More specifically, the chemicalsupplying device 100 according to the second embodiment is configured tobe in fluid communication with the second chemical supply source 30 forsupplying the second chemical via a pipe and supply a diluted secondchemical (second cleaning chemical) to the cleaning device 200.

The chemical supplying device 100 is provided with a second in-linemixer 73 and a second chemical CLC box 130. The second in-line mixer 73mixes the second chemical and DIW to generate a second cleaningchemical. The second chemical CLC box 130 controls a flow rate of thesecond chemical supplied from the second chemical supply source 30 tothe second in-line mixer 73.

The DIWCLC box 110 includes a second DIW supply valve 113. The secondDIW supply valve 113 switches ON/OFF of DIW supply from the CLC 111 tothe second in-line mixer 73. The CLC 111 measures a flow rate of the DIWto be supplied to the first in-line mixer 72 or the second in-line mixer73 and controls the flow rate based on this measured value.

The DIWCLC box 110 closes the second DIW supply valve 113 and opens thefirst DIW supply valve 112 to thereby supply the DIW to the firstin-line mixer 72. On the other hand, the DIWCLC box 110 closes the firstDIW supply valve 112 and opens the second DIW supply valve 113 tothereby supply the DIW to the second in-line mixer 73.

The second chemical CLC box 130 includes a second chemical supply valve132 and a CLC 131 (corresponding to an example of the chemical flow ratecontrol device). The second chemical supply valve 132 switches ON/OFF ofsecond chemical supply from the CLC 131 to the second in-line mixer 73.The CLC 131 measures a flow rate of the second chemical to be suppliedto the second in-line mixer 73 and controls the flow rate based on thismeasured value. More specifically, the CLC 131 adjusts (performsfeedback control) opening of a control valve inside the CLC 131 based onthe measured flow rate of the second chemical so that the flow rate ofthe second chemical flowing into the CLC 131 becomes a desired flowrate.

The chemical supplying device 100 is provided with a chemical utilitybox 60. The chemical utility box 60 introduces the second chemical fromthe second chemical supply source 30 to the CLC 131 of the secondchemical CLC box 130. The chemical utility box 60 is provided on a pipe92 that connects the second chemical supply source 30 and the CLC 131 ofthe second chemical CLC box 130. The chemical utility box 60 is providedwith a manual valve 63, a second chemical inlet valve 61 that switchesON/OFF of second chemical supply to the CLC 131 and a pressure gauge 62(corresponding to an example of the chemical IN-side pressure gauge)that measures a fluid pressure in the pipe 92. Opening/closing of thesecond chemical inlet valve 61 is controlled by, for example, a controldevice (not shown). Since the pipe 92 is connected to the CLC 131 of thesecond chemical CLC box 130, the pressure gauge 62 is configured tomeasure a pressure on the IN-side (primary side) of the CLC 131. Inother words, the pressure gauge 62 measures a pressure of the secondchemical flowing into the CLC 131.

A second DIW pipe 84 in fluid communication with the second in-linemixer 73 is connected to the CLC 111 of the DIWCLC box 110. One end ofthe second DIW pipe 84 is connected to the CLC 111. The other end of thesecond DIW pipe 84 is connected to a second chemical pipe 94 which willbe described later, at a confluence part 79 and is in fluidcommunication with the second in-line mixer 73. Note that as shown inFIG. 4, the confluence part 79 is a point at which the DIW from the CLC111 and the second chemical from the CLC 131 join together. The secondDIW supply valve 113 is provided on the second DIW pipe 84 andopening/closing thereof is controlled when the DIW is supplied to thesecond in-line mixer 73.

The second chemical pipe 94 in fluid communication with the secondin-line mixer 73 is connected to the CLC 131 of the second chemical CLCbox 130. The second chemical supply valve 132 is provided on the secondchemical pipe 94 and opening/closing thereof is controlled when thesecond chemical is supplied to the second in-line mixer 73. A secondcleaning chemical pipe 97, one end of which is connected to the chemicalcleaning section 220 is connected to the second in-line mixer 73. Apressure gauge 75 (corresponding to an example of the OUT-side pressuregauge) is provided on the OUT-side (secondary side) of the secondin-line mixer 73. Since the DIW from the CLC 111 of the DIWCLC box 110and the second chemical from the CLC 131 of the second chemical CLC box130 join together at the confluence part 79, a pressure on the OUT-side(secondary side) of the CLC 111 is equal to a pressure on the OUT-sideof the CLC 131. Therefore, this pressure gauge 75 can measure pressureson the OUT-side (secondary side) of the CLC 111 and the CLC 131. Inother words, the pressure gauge 75 measures pressures of liquids flowingout from the CLC 111 and the CLC 131.

The CLC 131 of the second chemical CLC box 130 is configured to be ableto receive a signal indicating a predetermined flow rate value from acontrol device (not shown). Opening of an inner control valve of the CLC131 is controlled based on this flow rate value.

Next, a chemical supply process will be described in which the chemicalsupplying device 100 shown in FIG. 4 supplies the first cleaningchemical and the second cleaning chemical to the chemical cleaningsection 220. When the first cleaning chemical is supplied to thechemical cleaning section 220 of the cleaning device 200, the firstchemical inlet valve 51 of the chemical utility box 50 is opened firstand the manual valve 53 is then opened. A flow rate of the firstchemical is adjusted by the CLC 121 of the first chemical CLC box 120and the first chemical at a predetermined flow rate is supplied from thefirst chemical supply source 20 to the first in-line mixer 72.

When the DIW supply valve 86 on the DIW supply pipe 81 is opened, theDIW is supplied from the DIW supply source 10 to the CLC 111 of theDIWCLC box 110. When the first DIW supply valve 112 is opened, the DIWis supplied from the DIWCLC box 110 to the first in-line mixer 72. Atthis time, the second DIW supply valve 113 should be closed.

The first chemical and DIW supplied to the first in-line mixer 72 aremixed. The first cleaning chemical generated in this way is supplied tothe chemical cleaning section 220 via the first cleaning chemical pipe96. While the first cleaning chemical is being supplied to the chemicalcleaning section 220, the supply of the second chemical to the secondin-line mixer 73 is stopped. More specifically, the second chemicalsupply valve 132 of the second chemical CLC box 130 is closed. Thus, thesecond cleaning chemical is not supplied, but only the first cleaningchemical is supplied to the chemical cleaning section 220.

While the first cleaning chemical is being supplied to the chemicalcleaning section 220, the pressure gauge 76, the pressure gauge 52 andthe pressure gauge 74 measure a pressure on the IN-side of the CLC 111,a pressure on the IN-side of the CLC 121 and pressures on the OUT-sideof the CLC 111 and the CLC 121 respectively. It is thereby possible toobtain a differential pressure between the IN-side pressure and theOUT-side pressure of the CLC 111 and a differential pressure between theIN-side pressure and the OUT-side pressure of the CLC 121.

When the second cleaning chemical is supplied to the chemical cleaningsection 220 of the cleaning device 200, the second chemical inlet valve61 of the chemical utility box 60 is opened first and the manual valve63 is then opened. The CLC 131 of the second chemical CLC box 130adjusts the flow rate of the second chemical and the second chemical ata predetermined flow rate is supplied from the second chemical supplysource 30 to the second in-line mixer 73.

When the DIW supply valve 86 on the DIW supply pipe 81 is opened, theDIW is supplied from the DIW supply source 10 to the CLC 111 of theDIWCLC box 110. When the second DIW supply valve 113 is opened, the DIWis supplied from the DIWCLC box 110 to the second in-line mixer 73. Atthis time, the first DIW supply valve 112 is closed.

The second chemical and the DIW are mixed at the second in-line mixer73. The second cleaning chemical generated in this way is supplied tothe chemical cleaning section 220 via the second cleaning chemical pipe97. While the second cleaning chemical is being supplied to the chemicalcleaning section 220, the supply of the first chemical to the firstin-line mixer 72 is stopped. More specifically, the first chemicalsupply valve 122 of the first chemical CLC box 120 is closed. Thus, thefirst cleaning chemical is not supplied, but only the second cleaningchemical is supplied to the chemical cleaning section 220.

While the second cleaning chemical is being supplied to the chemicalcleaning section 220, the pressure gauge 76, the pressure gauge 62, andthe pressure gauge 75 measure a pressure on the IN-side of the CLC 111,a pressure on the IN-side of the CLC 131 and pressures on the OUT-sideof the CLC 111 and the CLC 131 respectively. It is thereby possible toobtain a differential pressure between the IN-side pressure and theOUT-side pressure of the CLC 111 and a differential pressure between theIN-side pressure and the OUT-side pressure of the CLC 131.

As described above, the chemical supplying device 100 using a pluralityof chemicals as in the case of the second embodiment can also obtain adifferential pressure between the respective IN-side pressures and theOUT-side pressures of the CLCs 111, 121 and 131. Thus, the operatormonitors the differential pressure between the respective IN-sidepressures and the OUT-side pressures of the CLCs 111, 121 and 131, andcan thereby grasp whether the CLCs 111, 121 and 131 are malfunctioningor a differential pressure is insufficient as in the case of the firstembodiment. Furthermore, by acquiring the differential pressure betweenthe IN-side pressures and the OUT-side pressures of the CLCs 111, 121and 131 in advance, it is possible to easily select an appropriate CLCwhen changing any one of the CLCs 111, 121 and 131 in association with achange in the process recipe.

The embodiments of the present invention have been described so far, butthe aforementioned embodiments are intended to make an understanding ofthe present invention easier and not to limit the present invention. Thepresent invention may be changed or modified without departing from thespirit and scope of the present invention and it goes without sayingthat the present invention includes equivalents thereof. It is possibleto arbitrarily combine or omit the components described in the scope ofclaims and the specification within a scope that exerts at least part ofthe scope or effects within which at least some of the aforementionedproblems can be solved.

Hereinafter, some of aspects disclosed in the present specification willbe described.

According to a first aspect, a liquid supplying device for supplying aliquid from a liquid source to a cleaning device is provided. Thisliquid supplying device includes a flow rate control device configuredto measure a flow rate of the liquid from the liquid source and controlthe flow rate based on the measured value, an IN-side pressure gaugeprovided between the liquid source and the flow rate control device andan OUT-side pressure gauge provided between the flow rate control deviceand the cleaning device.

According to the first aspect, it is possible to obtain a differentialpressure between a pressure on the IN-side and a pressure on theOUT-side of the flow rate control device. Even when the flow ratecontrol device cannot supply a desired flow rate, the operator can graspwhether the flow rate control device is malfunctioning or thedifferential pressure is insufficient by monitoring this differentialpressure. When changing the flow rate control device in association witha change in the process recipe, it is possible to easily select anappropriate flow rate control device.

According to a second aspect, in the liquid supplying device accordingto the first aspect, the liquid source includes a dilution water supplysource and a chemical supply source. The flow rate control deviceincludes a dilution water flow rate control device configured to measurea flow rate of dilution water from the dilution water supply source andcontrol the flow rate based on the measured value and a chemical flowrate control device configured to measure a flow rate of a chemical fromthe chemical supply source and control the flow rate based on themeasured value. The liquid supplying device further includes aconfluence part at which the dilution water from the dilution water flowrate control device and the chemical from the chemical flow rate controldevice join together. The IN-side pressure gauge includes a chemicalIN-side pressure gauge provided between the chemical supply source andthe chemical flow rate control device. The OUT-side pressure gauge isprovided between the chemical flow rate control device or the dilutionwater flow rate control device and the cleaning device.

According to the second aspect, it is possible to measure an IN-sidepressure of the chemical flow rate control device using the chemicalIN-side pressure gauge. Since the dilution water from the dilution waterflow rate control device and the chemical from the chemical flow ratecontrol device join together at the confluence part, the pressure of thedilution water flowing out from the dilution water flow rate controldevice is equal to the pressure of the chemical flowing out from thechemical flow rate control device. Since the OUT-side pressure gauge isprovided between the chemical flow rate control device or the dilutionwater flow rate control device and the cleaning device, it is possibleto measure an OUT-side pressure of the chemical flow rate controldevice. It is thereby possible to acquire a differential pressurebetween the IN-side pressure and the OUT-side pressure of the chemicalflow rate control device.

According to a third aspect, in the liquid supplying device according tothe second aspect, the IN-side pressure gauge further includes adilution water IN-side pressure gauge provided between the dilutionwater supply source and the dilution water flow rate control device.

According to the third aspect, the IN-side pressure of the dilutionwater flow rate control device can be measured. Since the OUT-sidepressure of the dilution water flow rate control device can be measuredusing the OUT-side pressure gauge, it is possible to obtain adifferential pressure between the IN-side pressure and the OUT-sidepressure of the dilution water flow rate control device.

According to a fourth aspect, a liquid supplying method is provided fora liquid supplying device provided with a flow rate control deviceconfigured to measure a flow rate from a liquid source and control theflow rate based on the measured value, to supply a liquid from theliquid source to a cleaning device. This method includes a flow ratecontrolling step of measuring a flow rate from the liquid source andcontrolling the flow rate based on the measured value, a first measuringstep of measuring a pressure of a liquid flowing into the flow ratecontrol device, and a second measuring step of measuring a pressure of aliquid flowing out from the flow rate control device.

According to the fourth aspect, it is possible to obtain a differentialpressure between a pressure on the IN-side and a pressure on theOUT-side of the flow rate control device. Even when the flow ratecontrol device cannot supply a desired flow rate, the operator can graspwhether the flow rate control device is malfunctioning or thedifferential pressure is insufficient by monitoring this differentialpressure. When changing the flow rate control device in association witha change in the process recipe, it is possible to easily select anappropriate flow rate control device.

According to a fifth aspect, in the liquid supplying method according tothe fourth aspect, the flow rate control device includes a dilutionwater flow rate control device configured to measure a flow rate ofdilution water from the dilution water supply source and control theflow rate based on the measured value and a chemical flow rate controldevice configured to measure a flow rate of a chemical from the chemicalsupply source and control the flow rate based on the measured value. Theflow rate controlling step includes a dilution water flow ratecontrolling step of measuring a flow rate of the dilution water from thedilution water supply source and controlling the flow rate based on themeasured value and a chemical flow rate controlling step of measuring aflow rate of the chemical from the chemical supply source andcontrolling the flow rate based on the measured value. The liquidsupplying method further includes a step of joining the dilution water,a flow rate of which is controlled and the chemical, a flow rate ofwhich is controlled. The first measuring step includes a step ofmeasuring a pressure of a chemical flowing into the chemical flow ratecontrol device. The second measuring step includes a step of measuring apressure of any one of the chemical flowing out from the chemical flowrate control device, the dilution water flowing out from the dilutionwater flow rate control device and a mixed solution of the chemical andthe dilution water.

According to the fifth aspect, it is possible to measure an IN-sidepressure of the chemical flow rate control device. Furthermore, sincethe dilution water and the chemical join together, the pressure of thedilution water flowing out from the dilution water flow rate controldevice is equal to the pressure of the chemical flowing out from thechemical flow rate control device. It is therefore possible to measurean OUT-side pressure of the chemical flow rate control device bymeasuring a pressure of any one of the chemical flowing out from thechemical flow rate control device, dilution water flowing out from thedilution water flow rate control device and a mixed solution of thechemical and the dilution water. It is thereby possible to acquire adifferential pressure between the IN-side pressure and the OUT-sidepressure of the chemical flow rate control device.

According to a sixth aspect, in the liquid supplying method according tothe fifth aspect, the first measuring step includes a step of measuringa pressure of the dilution water flowing into the dilution water flowrate control device.

According to the sixth aspect, the IN-side pressure of the dilutionwater flow rate control device can be measured. Since the OUT-sidepressure of the dilution water flow rate control device is measured inthe second measuring step, it is possible to obtain a differentialpressure between the IN-side pressure and the OUT-side pressure of thedilution water flow rate control device.

REFERENCE SIGNS LIST

-   -   10 . . . DIW supply source    -   20 . . . First chemical supply source    -   30 . . . Second chemical supply source    -   52 . . . Pressure gauge    -   62 . . . Pressure gauge    -   74 . . . Pressure gauge    -   75 . . . Pressure gauge    -   76 . . . Pressure gauge    -   78 . . . Confluence part    -   79 . . . Confluence part    -   100 . . . Chemical supplying device    -   111 . . . CLC    -   121 . . . CLC    -   131 . . . CLC    -   200 . . . Cleaning device

What is claimed is:
 1. A device for generating a mixed liquid by mixinga liquid from a first liquid source and a liquid from a second liquidsource, comprising: a flow rate control device configured to measure aflow rate of a liquid from the first liquid source and control the flowrate based on the measured value; an IN-side pressure gauge providedbetween the first liquid source and the flow rate control device; and anOUT-side pressure gauge provided at downstream side of the flow ratecontrol device, wherein a confluence part that is a point of confluencewhere the liquid from the first liquid source and the liquid from thesecond liquid source joint together is provided between the OUT-sidepressure gauge and the flow rate control device.
 2. The device accordingto claim 1, further comprising a first chemical CLC box, wherein theflow rate control device is housed in the first chemical CLC box.
 3. Thedevice according to claim 1, further comprising a chemical utility box,wherein the IN-side pressure gauge is housed in the chemical utilitybox.
 4. The device according to claim 3, wherein the OUT-side pressuregauge is provided outside of the chemical utility box.
 5. The deviceaccording to claim 1, wherein the device is configured to supply themixed liquid to a cleaning device that cleans a substrate.
 6. A liquidsupplying device, comprising: a housing, a DIWCLC box housed in thehousing, the DIWCLC box suppling a DIW supplied from a DIW supply sourcethrough an IN-side pressure gauge configured to measure a pressure ofthe DIW to a first pipe connected to a discharge side of the DIWCLC box,and comprising a flow rate control device configured to control a flowrate of the DIW inside the pipe housed therein, a first chemical CLC boxhoused in the housing, the first chemical CLC box supplying a firstchemical supplied from a first chemical supply source to a second pipeand controlling a flow rate of the first chemical, a confluence parthoused in the housing, the confluence part being a point of confluencewhere the first pipe and the second pipe joint together, an OUT-sidepressure gauge housed in the housing and configured to measure apressure of a mixed liquid generated by mixing the DIW and the firstchemical at the confluence part, and a third pipe housed in the housingand configured to discharge the mixed liquid that has been passedthrough the OUT-side pressure gauge to outside of the housing.
 7. Aliquid supplying device, comprising: a chemical utility box comprisingan IN-side pressure gauge that measures a pressure of a chemicalsupplied from a chemical supply source, a chemical CLC box comprising afirst flow rate control device configured to control a flow rate of thechemical, and connected to downstream side of the chemical utility box,a chemical discharge pipe connected to downstream side of the chemicalCLC box, a DIWCLC box comprising a second flow rate control deviceconfigured to control a flow rate of a DIW supplied from a DIW supplysource, a DIW discharge pipe connected to downstream side of the DIW CLCbox, a confluence part that is a point of confluence where the chemicaldischarge pipe and the DIW discharge pipe joint together, an OUT-sidepressure gauge configured to measure a pressure of a mixed liquidgenerate by mixing the DIW and the first chemical at the confluencepart, and a discharge pipe connected to the OUT-side pressure gauge.